This book deals with neutral particle flow in a stochastic mixture consisting of two or more immiscible fluids. After giving an introduction to linear kinetic theory and particle transport in a nonstochastic setting, it discusses recent formulations for particle flow through a background material whose properties are only known in a statistical sense. The mixing descriptions considered are both Markovian and renewal statistics. Various models and exact results are presented for the ensemble average of the intensity in such stochastic mixtures. In the Markovian case, the underlying kinetic description is the integro-differential transport equation, whereas for renewal statistics the natural starting point is the purely integral formulation of transport theory.